Pre-requirements

  • Be comfortable with the UNIX command line

    • navigating directories

    • editing files

    • a little bit of bash-fu (environment variables, loops)

  • Some Docker knowledge

    • docker run, docker ps, docker build

    • ideally, you know how to write a Dockerfile and build it
      (even if it's a FROM line and a couple of RUN commands)

  • It's totally OK if you are not a Docker expert!

Tell me and I forget.
Teach me and I remember.
Involve me and I learn.

Misattributed to Benjamin Franklin

(Probably inspired by Chinese Confucian philosopher Xunzi)

Hands-on sections

  • The whole workshop is hands-on

  • We are going to build, ship, and run containers!

  • You are invited to reproduce all the demos

  • All hands-on sections are clearly identified, like the gray rectangle below

  • This is the stuff you're supposed to do!

  • Go to @@SLIDES@@ to view these slides

  • Join the chat room: @@CHAT@@

Where are we going to run our containers?

You get a cluster
Figure 26 : You get a cluster

You get a cluster of cloud VMs

  • Each person gets a private cluster of cloud VMs (not shared with anybody else)

  • They'll remain up for the duration of the workshop

  • You should have a little card with login+password+IP addresses

  • You can automatically SSH from one VM to another

  • The nodes have aliases: node1, node2, etc.

Why don't we run containers locally?

  • Installing that stuff can be hard on some machines

    (32 bits CPU or OS... Laptops without administrator access... etc.)

  • "The whole team downloaded all these container images from the WiFi!
    ... and it went great!"     (Literally no-one ever)

  • All you need is a computer (or even a phone or tablet!), with:

    • an internet connection

    • a web browser

    • an SSH client

SSH clients

What is this Mosh thing?

You don't have to use Mosh or even know about it to follow along.
We're just telling you about it because some of us think it's cool!

  • Mosh is "the mobile shell"

  • It is essentially SSH over UDP, with roaming features

  • It retransmits packets quickly, so it works great even on lossy connections

    (Like hotel or conference WiFi)

  • It has intelligent local echo, so it works great even in high-latency connections

    (Like hotel or conference WiFi)

  • It supports transparent roaming when your client IP address changes

    (Like when you hop from hotel to conference WiFi)

Using Mosh

  • To install it: (apt|yum|brew) install mosh

  • It has been pre-installed on the VMs that we are using

  • To connect to a remote machine: mosh user@host

    (It is going to establish an SSH connection, then hand off to UDP)

  • It requires UDP ports to be open

    (By default, it uses a UDP port between 60000 and 61000)

Connecting to our lab environment

  • Log into the first VM (node1) with your SSH client
  • Check that you can SSH (without password) to node2:
    ssh node2
  • Type exit or ^D to come back to node1

If anything goes wrong — ask for help!

Doing or re-doing the workshop on your own?

  • Use something like Play-With-Docker or Play-With-Kubernetes

    Zero setup effort; but environment are short-lived and might have limited resources

  • Create your own cluster (local or cloud VMs)

    Small setup effort; small cost; flexible environments

  • Create a bunch of clusters for you and your friends (instructions)

    Bigger setup effort; ideal for group training

Get your own Docker nodes

  • If you already have some Docker nodes: great!

  • If not: let's get some thanks to Play-With-Docker

You will need a Docker ID to use Play-With-Docker.

(Creating a Docker ID is free.)

We will (mostly) interact with node1 only

These remarks apply only when using multiple nodes, of course.

  • Unless instructed, all commands must be run from the first VM, node1

  • We will only checkout/copy the code on node1

  • During normal operations, we do not need access to the other nodes

  • If we had to troubleshoot issues, we would use a combination of:

    • SSH (to access system logs, daemon status...)

    • Docker API (to check running containers and container engine status)

Terminals

Once in a while, the instructions will say:
"Open a new terminal."

There are multiple ways to do this:

  • create a new window or tab on your machine, and SSH into the VM;

  • use screen or tmux on the VM and open a new window from there.

You are welcome to use the method that you feel the most comfortable with.

Tmux cheatsheet

Tmux is a terminal multiplexer like screen.

You don't have to use it or even know about it to follow along.
But some of us like to use it to switch between terminals.
It has been preinstalled on your workshop nodes.

  • Ctrl-b c → creates a new window
  • Ctrl-b n → go to next window
  • Ctrl-b p → go to previous window
  • Ctrl-b " → split window top/bottom
  • Ctrl-b % → split window left/right
  • Ctrl-b Alt-1 → rearrange windows in columns
  • Ctrl-b Alt-2 → rearrange windows in rows
  • Ctrl-b arrows → navigate to other windows
  • Ctrl-b d → detach session
  • tmux attach → reattach to session